Message-ID: <548b2225-a395-ca52-15cf-ee4f3dd5cd93@axis.com>
Date:   Tue, 13 Dec 2016 09:26:19 +0100
From:   Niklas Cassel <niklas.cassel@...s.com>
To:     Giuseppe CAVALLARO <peppe.cavallaro@...com>,
        Alexandre Torgue <alexandre.torgue@...com>
CC:     <netdev@...r.kernel.org>
Subject: Re: stmmac DT property snps,axi_all

On 12/13/2016 07:47 AM, Giuseppe CAVALLARO wrote:
> Hello Niklas, Alex,
>
> my fault and a step behind... Current code is OK
> when manage the AAL that, although it is passed from
> the axi structure, it is always used to program,
> for all the chip versions, the writable bit inside the
> DMA_BUS_MODE register.
> So I guess no extra patch is needed.

Hello Giuseppe

I'm not sure what you mean.

Yes, when setting "snps,aal",
the code is correct for all versions of the IP.

However, "snps,axi_all" seems to just be dead code.
Try git grep in the whole tree.
So I still think that my patch is valid.


>
> Regards
> Peppe
>
> On 12/12/2016 3:18 PM, Giuseppe CAVALLARO wrote:
>> Please Niklas
>>
>> when you send the patch, add my
>>
>> Acked-by: Giuseppe Cavallaro <peppe.cavallaro@...com>
>>
>>
>> On 12/9/2016 10:53 AM, Niklas Cassel wrote:
>>> On 12/09/2016 10:20 AM, Niklas Cassel wrote:
>>>> On 12/08/2016 02:36 PM, Alexandre Torgue wrote:
>>>>> Hi Niklas,
>>>>>
>>>>> On 12/05/2016 05:18 PM, Niklas Cassel wrote:
>>>>>> Hello Giuseppe
>>>>>>
>>>>>>
>>>>>> I'm trying to figure out what snps,axi_all is supposed to represent.
>>>>>>
>>>>>> It appears that the value is saved, but never used in the code.
>>>>>>
>>>>>> Looking at the register specification, I'm guessing that it represents
>>>>>> Address-Aligned Beats, but there is already the property snps,aal
>>>>>> for that.
>>>>> IMO, it is not useful. Indeed AXI_AAL is a read only bit (in AXI bus
>>>>> mode register) and reflects the aal bit in DMA bus register.
>>>>> As you know we use "snps,aal" to set aal bit in DMA bus register.
>>>>> So "snps,axi_all" entry seems useless. Let's see with Peppe.
>>>> Ok, I see. GMAC and GMAC4 is different here.
>>>>
>>>> For GMAC4 AAL only exists in DMA_SYS_BUS_MODE.
>>>> It's not reflected anywhere else.
>>>>
>>>> The code is correct in the driver.
>>>>
>>>> If snps,axi_all is just created for a read-only register,
>>>> and it is currently never used in the code,
>>>> while we have snps,aal, which is correct and works,
>>>> I guess it should be ok to remove snps,axi_all.
>>>>
>>>> I can cook up a patch.
>>>>
>>>
>>> Here we go :)
>>>
>>> I will send it as a real patch once net-next reopens.
>>>
>>>
>>>> From defc01cb7c22611b89d9cf1fcae72544092bd62c Mon Sep 17 00:00:00 2001
>>> From: Niklas Cassel <niklas.cassel@...s.com>
>>> Date: Fri, 9 Dec 2016 10:27:00 +0100
>>> Subject: [PATCH net-next] net: stmmac: remove unused duplicate property
>>>  snps,axi_all
>>>
>>> For core revision 3.x Address-Aligned Beats is available in two
>>> registers.
>>> The DT property snps,aal was created for AAL in the DMA bus register,
>>> which is a read/write bit.
>>> The DT property snps,axi_all was created for AXI_AAL in the AXI bus mode
>>> register, which is a read only bit that reflects the value of AAL in the
>>> DMA bus register.
>>>
>>> Since the value of snps,axi_all is never used in the driver,
>>> and since the property was created for a bit that is read only,
>>> it should be safe to remove the property.
>>>
>>> Signed-off-by: Niklas Cassel <niklas.cassel@...s.com>
>>> ---
>>>  Documentation/devicetree/bindings/net/stmmac.txt      | 1 -
>>>  drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c | 1 -
>>>  include/linux/stmmac.h                                | 1 -
>>>  3 files changed, 3 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/net/stmmac.txt
>>> b/Documentation/devicetree/bindings/net/stmmac.txt
>>> index 128da752fec9..c3d2fd480a1b 100644
>>> --- a/Documentation/devicetree/bindings/net/stmmac.txt
>>> +++ b/Documentation/devicetree/bindings/net/stmmac.txt
>>> @@ -65,7 +65,6 @@ Optional properties:
>>>      - snps,wr_osr_lmt: max write outstanding req. limit
>>>      - snps,rd_osr_lmt: max read outstanding req. limit
>>>      - snps,kbbe: do not cross 1KiB boundary.
>>> -    - snps,axi_all: align address
>>>      - snps,blen: this is a vector of supported burst length.
>>>      - snps,fb: fixed-burst
>>>      - snps,mb: mixed-burst
>>> diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> index 082cd48db6a7..60ba8993c650 100644
>>> --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c
>>> @@ -121,7 +121,6 @@ static struct stmmac_axi *stmmac_axi_setup(struct
>>> platform_device *pdev)
>>>      axi->axi_lpi_en = of_property_read_bool(np, "snps,lpi_en");
>>>      axi->axi_xit_frm = of_property_read_bool(np, "snps,xit_frm");
>>>      axi->axi_kbbe = of_property_read_bool(np, "snps,axi_kbbe");
>>> -    axi->axi_axi_all = of_property_read_bool(np, "snps,axi_all");
>>>      axi->axi_fb = of_property_read_bool(np, "snps,axi_fb");
>>>      axi->axi_mb = of_property_read_bool(np, "snps,axi_mb");
>>>      axi->axi_rb =  of_property_read_bool(np, "snps,axi_rb");
>>> diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
>>> index 266dab9ad782..889e0e9a3f1c 100644
>>> --- a/include/linux/stmmac.h
>>> +++ b/include/linux/stmmac.h
>>> @@ -103,7 +103,6 @@ struct stmmac_axi {
>>>      u32 axi_wr_osr_lmt;
>>>      u32 axi_rd_osr_lmt;
>>>      bool axi_kbbe;
>>> -    bool axi_axi_all;
>>>      u32 axi_blen[AXI_BLEN];
>>>      bool axi_fb;
>>>      bool axi_mb;
>>>
>>
>>
>

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